The present invention relates to data center infrastructure, and more particularly, this invention relates to a flow based overlay network architecture and components thereof.
Network virtualization is an emerging data center and cloud computing trend which aims to virtualize a network as seen by end stations in a way that greatly simplifies network provisioning in multi-tenant environments, as well as traditional environments. One of the more common techniques of achieving network virtualization is to use network overlays, where tunnels are established between servers, edge network switches, and gateways to which end stations connect. The tunnel is actually implemented by encapsulating packets transmitted by a source end station into an overlay header that transports the packet from the source switch to a target switch in user datagram protocol (UDP) transport via an internet protocol (IP)-based network. The overlay header includes an identifier (ID) that uniquely identifies the virtual network. The target switch strips off the overlay header encapsulation, UDP transport header, and IP header, and delivers the original packet to the destination end station. In addition to this tunneling mechanism, the edge switches participate in an address discovery protocol, which may be learning/flooding based, or lookup-based.
Overlay networks like Virtual eXtensible Local Area Network (VXLAN) connect geographically separated Layer-2 (L2) networks using tunnels. These are L2 over Layer-3 (L3) tunnels. L2 packets originated by a virtual machine (VM) in a VXLAN and destined to another VM or group of VMs in same VXLAN in another physical location are carried over L3 tunnels.
Overlay networks are complex to manage. One reason for this complexity is that network administrators manage networks, while server administrators manage servers. Both the network and server administrators need to work together to manage an overlay network, which may make use of both entities in the overlay architecture. This added complexity may result in miscommunication resulting in some tasks being performed twice, some tasks not being performed (as an administrator may assume the other is handling it), and overall delay due to the cooperation being needed. Accordingly, it would be beneficial to have an overlay network which could be managed by one administrator.